Add samples for some of the functions

src/stream/double_ended/mod.rs

@@ -37,10 +37,10 @@ extension_trait! {
             ```
             # fn main() { async_std::task::block_on(async {
             #
+            use async_std::stream::Sample;
             use async_std::stream::double_ended::DoubleEndedStreamExt;
-            use async_std::stream;
 
-            let mut s = stream::from_iter(vec![1u8, 2, 3, 4, 5]);
+            let mut s = Sample::from(vec![1u8, 2, 3, 4, 5]);
 
             let second = s.nth_back(1).await;
             assert_eq!(second, Some(4));
@@ -58,6 +58,27 @@ extension_trait! {
             NthBackFuture::new(self, n)
         }
 
+        #[doc = r#"
+            Returns the the frist element from the right that matches the predicate.
+
+            # Examples
+
+            Basic usage:
+
+            ```
+            # fn main() { async_std::task::block_on(async {
+            #
+            use async_std::stream::Sample;
+            use async_std::stream::double_ended::DoubleEndedStreamExt;
+
+            let mut s = Sample::from(vec![1u8, 2, 3, 4, 5]);
+
+            let second = s.rfind(|v| v % 2 == 0).await;
+            assert_eq!(second, Some(4));
+            #
+            # }) }
+            ```
+        "#]
         fn rfind<P>(
             &mut self,
             p: P,
@@ -69,6 +90,26 @@ extension_trait! {
             RFindFuture::new(self, p)
         }
 
+        #[doc = r#"
+            # Examples
+
+            Basic usage:
+
+            ```
+            # fn main() { async_std::task::block_on(async {
+            #
+            use async_std::stream::Sample;
+            use async_std::stream::double_ended::DoubleEndedStreamExt;
+
+            let s = Sample::from(vec![1, 2, 3, 4, 5]);
+
+            let second = s.rfold(0, |acc, v| v + acc).await;
+
+            assert_eq!(second, 15);
+            #
+            # }) }
+            ```
+        "#]
         fn rfold<B, F>(
             self,
             accum: B,

src/stream/double_ended_stream.rs

@@ -22,31 +22,3 @@ pub trait DoubleEndedStream: Stream {
     /// [trait-level]: trait.DoubleEndedStream.html
     fn poll_next_back(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>;
 }
-
-pub struct Sample<T> {
-    inner: Vec<T>,
-}
-
-impl<T> From<Vec<T>> for Sample<T> {
-    fn from(data: Vec<T>) -> Self {
-        Sample { inner: data }
-    }
-}
-
-impl<T> Unpin for Sample<T> {}
-
-impl<T> Stream for Sample<T> {
-    type Item = T;
-    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        if self.inner.len() > 0 {
-            return Poll::Ready(Some(self.inner.remove(0)));
-        }
-        return Poll::Ready(None);
-    }
-}
-
-impl<T> DoubleEndedStream for Sample<T> {
-    fn poll_next_back(mut self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        Poll::Ready(self.inner.pop())
-    }
-}

src/stream/mod.rs

@@ -307,8 +307,9 @@ pub use once::{once, Once};
 pub use repeat::{repeat, Repeat};
 pub use repeat_with::{repeat_with, RepeatWith};
 pub use stream::*;
+pub use crate::stream::sample::Sample;
 
-pub(crate) mod stream;
+pub mod stream;
 
 mod empty;
 mod from_fn;
@@ -316,6 +317,7 @@ mod from_iter;
 mod once;
 mod repeat;
 mod repeat_with;
+mod sample;
 
 cfg_unstable! {
     pub mod double_ended;

src/stream/sample.rs

@@ -0,0 +1,33 @@
+use crate::stream::Stream;
+
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use crate::stream::DoubleEndedStream;
+
+pub struct Sample<T> {
+    inner: Vec<T>,
+}
+
+impl<T> From<Vec<T>> for Sample<T> {
+    fn from(data: Vec<T>) -> Self {
+        Sample { inner: data }
+    }
+}
+
+impl<T> Unpin for Sample<T> {}
+
+impl<T> Stream for Sample<T> {
+    type Item = T;
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        if self.inner.len() > 0 {
+            return Poll::Ready(Some(self.inner.remove(0)));
+        }
+        return Poll::Ready(None);
+    }
+}
+
+impl<T> DoubleEndedStream for Sample<T> {
+    fn poll_next_back(mut self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        Poll::Ready(self.inner.pop())
+    }
+}